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  <title>Get the boolean value of a variable</title>

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</div><hr /><div id="function.boolval" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">boolval</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.5.0)</p><p class="refpurpose"><span class="refname">boolval</span> &mdash; <span class="dc-title">Get the boolean value of a variable</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-function.boolval-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="type">boolean</span> <span class="methodname"><strong>boolval</strong></span>
    ( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$var</code></span>
   )</div>

  <p class="para rdfs-comment">
   Returns the <span class="type"><a href="language.types.boolean.html" class="type boolean">boolean</a></span> value of <em><code class="parameter">var</code></em>.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.boolval-parameters">
  <h3 class="title">参数</h3>
  <dl>

   
    <dt>
<em><code class="parameter">var</code></em></dt>

    <dd>

     <p class="para">
      The scalar value being converted to a <span class="type"><a href="language.types.boolean.html" class="type boolean">boolean</a></span>.
     </p>
    </dd>

   
  </dl>

 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.boolval-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   The <span class="type"><a href="language.types.boolean.html" class="type boolean">boolean</a></span> value of <em><code class="parameter">var</code></em>.
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.boolval-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-5146">
    <p><strong>Example #1 <span class="function"><strong>boolval()</strong></span> examples</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #DD0000">'0:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">0</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'42:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">42</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'0.0:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">0.0</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'4.2:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">4.2</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"":&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">""</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"string":&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">"string"</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"0":&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">"0"</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"1":&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">"1"</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'[1,&nbsp;2]:&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">([</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">])&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'[]:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">([])&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'stdClass:&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(new&nbsp;</span><span style="color: #0000BB">stdClass</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
0:        false
42:       true
0.0:      false
4.2:      true
&quot;&quot;:       false
&quot;string&quot;: true
&quot;0&quot;:      false
&quot;1&quot;:      true
[1, 2]:   true
[]:       false
stdClass: true
</pre></div>
    </div>
   </div>
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.boolval-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.floatval.html" class="function" rel="rdfs-seeAlso">floatval()</a> - 获取变量的浮点值</span></li>
    <li class="member"><span class="function"><a href="function.intval.html" class="function" rel="rdfs-seeAlso">intval()</a> - 获取变量的整数值</span></li>
    <li class="member"><span class="function"><a href="function.strval.html" class="function" rel="rdfs-seeAlso">strval()</a> - 获取变量的字符串值</span></li>
    <li class="member"><span class="function"><a href="function.settype.html" class="function" rel="rdfs-seeAlso">settype()</a> - 设置变量的类型</span></li>
    <li class="member"><span class="function"><a href="function.is-bool.html" class="function" rel="rdfs-seeAlso">is_bool()</a> - 检测变量是否是布尔型</span></li>
    <li class="member"><a href="language.types.type-juggling.html" class="link">Type juggling</a></li>
   </ul>
  </p>
 </div>

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